$A$ $2\,\mu F$ capacitor is charged to a potential of $10\,V$. Another $4\,\mu F$ capacitor is charged to a potential of $20\,V$. The two capacitors are then connected in a single loop,with the positive plate of one connected to the negative plate of the other. What heat is evolved in the circuit in $\mu J$?

Two capacitors of capacitance $2 \ \mu F$ and $5 \ \mu F$ are charged to $2 \ V$ and $10 \ V$ respectively. Find the ratio of their charges after they are connected by a wire.

The capacities of two conductors are $C_1$ and $C_2$ and their respective potentials are $V_1$ and $V_2$. If they are connected by a thin wire,then the loss of energy will be given by

Two charged spheres of radii $a$ and $b$ are connected by a wire. The ratio of the electric fields on their surfaces $E_a/E_b$ is:

$A$ $400\, pF$ capacitor is charged with a $100\, V$ battery. After disconnecting the battery,this capacitor is connected to another uncharged $400\, pF$ capacitor. Find the energy loss.

$A$ capacitor of capacitance $20 \mu F$ is charged by a battery of potential $24.3 \ V$. The capacitor is then disconnected from the battery and is connected to another uncharged capacitor of capacitance $10 \mu F$. After some time,the second capacitor is disconnected,discharged fully,and is again connected to the first capacitor. If the process is repeated several times,the charge on the first capacitor at the end of the fifth process is . . . . . . $\mu C$.